To facilitate storage, a conventional four-section umbrella framework can be collapsed inward from the tail frame member of the umbrella because of a flexible frame member attached to and in between the second main frame member and the inner end of the umbrella tail frame member. The inner end of the flexible frame member (5) is fastened to the second main frame member by a rivet (7), which also serves as a hinge pin, wherein the inner end of the flexible frame member (5) is of a circular structure connecting ring (52) placed around the rivet (7) which, when the umbrella is opened, also provides for the active rotation of flexible frame member (5), with a relatively large slot (25) in the end section of the second main frame member that accommodates the movement of the flexible frame member (5). Due to the placement of the relatively large slot (25) in this kind of conventional structure, it is not difficult to undermine the structural strength of the umbrella framework and, furthermore, it is necessary to insert a rivet (7) and include a hinge structure, which results in troublesome manufacturing procedures, wasted time and effort and higher production costs. Therefore, such conventional umbrella frameworks do not conform to principles of practicality.
In view of this, the main objective of the invention herein is to overcome the aforementioned disadvantages by utilizing an innovative and improved structure that enables umbrella frameworks to be constructed and assembled in an extremely simple manner while, furthermore, ensuring structural strength. The following attached drawings illustrate the structural characteristics and functions of the invention herein.